Idles Up and Down All Day - Toyota Nation Forum : Toyota Car and Truck Forums

remeinc · 02-07-2009, 10:44 AM

Need some help guys, I have an 88 Supra 7MGE stick, It idles up and down... no leaks on any hoses, bought a new MAF and that's not it, bought a new TPS and that's not it... bird cage light is on "when cold" then goes away...
Gave me a code of 24, air intake temperature (inside the MAF).

What in the world....anyone have any ideas?
RUNS REAL STRONG, NO SMOKE, NO NOTHING....only idles up and down when stop....

Mr. Lahey · 02-10-2009, 11:24 PM

My supra did that for a while. People always thought I was trying to race them at the lights. It was awkward. I think it was a vacuum leak. Look for a vacuum leak.

remeinc · 02-11-2009, 06:17 AM

Same here pleople look at me like I'm stupido or something....but I check for vacumm leaks (test) there are none to be found.

***bgrieger*** · 02-11-2009, 08:22 AM

If you have a new MAF and the air temp is showing, you may have bad wiring or a bad ecu. Erratic idle can also be caused by leaks in the intake after the AFM or a bad or sticking idle control valve.

remeinc · 02-11-2009, 08:59 AM

Thank you I will look into it...will let you know.

Thanks Again...

Christian87N · 02-26-2009, 09:33 PM

Quote:

Originally Posted by bgrieger

If you have a new MAF and the air temp is showing, you may have bad wiring or a bad ecu. Erratic idle can also be caused by leaks in the intake after the AFM or a bad or sticking idle control valve.

i second the bad idle control valve. I had a GS-R that did the same thing and it was a faulty ICV.

remeinc · 02-27-2009, 06:06 AM

Quote:

Originally Posted by Christian87N

i second the bad idle control valve. I had a GS-R that did the same thing and it was a faulty ICV.

remeinc · 02-27-2009, 06:07 AM

thank you, very expensive part looking for a used one.....

Jeeves · 02-27-2009, 06:49 AM

My supra did this and rather than the ISC being bad, several of the wires going to it had either been strained or just aged and had broken. Some wire and some soldering later and everything worked as it should. Since it's an elaborate stepper motor if it can't hit some of the "steps" it will jump from one extreme to the other making it idle up and down.

***bgrieger*** · 02-27-2009, 08:12 AM

Did you find the air temp problem in your brand new MAF yet? If it is a wiring issue, you can throw parts at it all day long and not solve anything.

Christian87N · 03-06-2009, 02:11 AM

did you find the problem? For the idle control valve, i'd say go to some junk yard that specializes in japanese cars. Does anyone know if a valve from a N/A engine will work with a turbo? Maybe you can leach one off a regular 2JZGE

Jeeves · 03-06-2009, 10:56 AM

Quote:

Originally Posted by Christian87N

did you find the problem? For the idle control valve, i'd say go to some junk yard that specializes in japanese cars. Does anyone know if a valve from a N/A engine will work with a turbo? Maybe you can leach one off a regular 2JZGE

The N/A and GTE's didn't change that component.